Pulsator for milking machines



Sept. 8, 1931. A. F. PLINT PULSATOR FOR MILKING MACHINES Filed Oct. 25, 1929 Patented Sept. 8, 1931 UNITED ySTATES PATENT OFFICE ALEXANDER FREDERICK PLIN T, HENIJBY-ON-THAMES, ENGLAD, ASSIGNOR T STUART TURNER LIMITED, 0F HENLEY-ON-THAMES, OXFORD, ENGLAND rLsATon non MILKING MACHINES Application led October 28, 1929, Serial No. 401,675, and in Great Britain October 29; 1928.

This invention relates to pulsators for milking machines, and has more especial reference to pulsators operating in association with a source of suction.

The main object of the present invention is to provide a pulsator which will be unaffected by changes in temperature and to simplify4 its construction by reducing the number of working parts so as to avoid friclo tion and remove the necessity for adjustment, whereby the pulsator may function over long periods without requiring overhaul, and a second object isl to provide for a steady and even pulsation throughout the operation.`

Further and favourable objects will appear from the followingdescription.

' In accordance with the invention a pulsator for milking machines comprises a pair of diaphragms of different superficial areas located in a casing, the smaller being open at one side to atmosphere, suction conduits in said casing, one leading to a closed space between said diaphragms and maintaining it f' evacuated, and the second conduit communi- -cating wlth a closed space between the larger diaphragm and the casing and a valve connected to said`1diaphragms and controlled by their positionto open said second space Atoatmosphere through said second conduit or to exhaust said space therethrough, whereby such space is intermittently evacuated on a suction being applied andpulsations of the diaphragms result.

The pulsation of the diaphragms effects osicillation of the valve, and preferably also alternates the suction between two conduits connected with the teat cups associated with the milk pipes with the result that the intermittent suction required for the milking operation'is produce -In a preferred form of pulsator according to the invention the casing contains a pair of diaph-ragms of different superficial area dividing it into three spaces, the middle and closed space being always connected to the source of suction or exhauster which main'- tains a partial vacuum therein and a second closed space between the larger diaphragm andthe casing'being connected alternately to ting the pulsations of the diaphragms to the' control valve, which conveniently reciprol cates in a cylindrical seating situated preferably in the bottom of the pulsator casing, the distributor lports from the exhaust-er or other source of suction to said spaces and to the teat cups branching from this seating.

The casing may conveniently be made of metal and the dlaphragms of rubber, rubberized fabric, fiexible metal or other airproof material, all connections of the pulsator being made air-tight and suitable packing employed Where necessary.

The invention will be further described with reference to the accompanying eXplanat'oi'y drawings hwhere two embodiments of pulsator according to the invention are illustrated by way of example, and where:

Fig. l is a vertical section of one form of pulsator with the control valve in the upper position;

Fig. 2 is a detail section .of the lower portion of the pulsator with the control valve in its lower position; 1

Fig. 3 shows a pair of teat cups in section and side elevation respectively for connection to the pulsator illustrated in the preceding figures; and

Fig. 4 is a vertical section of a modified construction.

Referring now to the drawings, but first more particularly to Figs. l and 2, l is a cylindrical casing formed, say, of cast iron or other suitable material, having a substantially circular interior cavity 2 surmounted periphery 7 secured to said annular collar in an air-tight fashion by a flanged head 8, thehead 8, the diaphragm 6, collar 5, diaphragm 3 and casing 1 being arranged to be secured and maintained as -a unit by a series of stud bolts 9 arranged peripherally-in the head 8 and projecting downwardly into the walls ofthe casing 1. I

A suction suppl pipe 10 from a suitable source of suction not shown) connects with the casing 1 at 11 and branches into two conduits 12 and 13, the conduit 12 passing upwards through the wall of the casing 1 and opening through the interior of the annular collar 5 at 14 into the space between the diaphragms 3 and 6.

The conduit 13 leads to a cylindrical valve seating 15 arranged in a Asolid p ortion 16 provided at the lower end of the casing 1, and in which a valve 17, hereafter more fully described, is located.

Secured to the lower and smaller diaphragm 3 on its underside is a small head 18, a bolt 19 passing from said head through the diaphragm 3 into a dumb-bell connection' 20 which serves simultaneously for mounting the head 18 and as a distance piece between the lower diaphragm 3 and the upper diaphragm 6. As, will be seen the head 18 must be secured to the diaphragm 3 at 21 with an air-tight joint.

Pivoted to the head 18 at 22 and 23 respectively are a pair of levers 24 and 25, which depend downwardly and across which a tension spring 26 is located, the free lower ends of the levers having rollers 27 and 28 respectively engaging the head 29 of the valve 17 already mentioned.

y The valve 17 has a central bore30 opening to atmosphere at its lower end 31 and to two annular cavities 32 and 33 formed, the first between the head 29 and a peripheral flange 34 on the valve 17, and the second between a guide 35 and a peripheral flange 36 on said valve, the guide 35 having an enlarged sole 37 which constitutes a stop limiting the travel of the valve 17 by coming into abutment with the lower face of the casing .1 at the limit of its upward travel and with a cap 38 secured thereto at the limit of its downward travel, the cap 38 being perforated on its underside at 39 to permit of the central bore 30 of the valve 17 opening to atmosphere.

Between the flanges 34 and 36 is a further annular cavity 40 which in Fig. 1 connects the suction conduit 13 with conduits 41 and 42 oppositely disposed within the casing 1, the conduit 42 leading` upwardly throughthe casing wall and opening at 43 into the space 44 between the upper and larger diaphragm V"6` and the head 8 of the pulsator.

As will be seen in the position shown in Fig. 1 the valve 17 is in its upper position, and so'the conduit 13 as just described connects with the conduits 41 and 42 in which event the suction is applied to the space 44, while in the position shown in Fig. 2 with the valve in its lower osition, the conduit 13 is through the annu ar cavity '40 thrown into connection with a lower conduit 45.

In the upper position of the valve 17 the conduit 45 is open to atmosphere through the bore 30 of the valve, and in the lower position of the valve the conduits 41 and 42 are open to atmosphere, the arrangement being such that when the conduit '45 is open to atmosphere the conduits 41 and 42 are subjected to suction and vice versa.

The head 29 of the valve 17 is arranged in the form of a double cone, the bases of the cones being contiguous at 46 and the crosssectioiial area of the head 29 diminishing on each side of 46 to provide what are in fact cam surfaces 47 and 48 for the rollers 27 and 28 aforementioned.

It will be readily understood that under the action of the tension spring 26 when the rollers bear on the lower cam surface 48 the valve 17 is induced to rise and keep its upper position as shown in Fig. 1, while when the rollers 27 and 28 occupy the upper cam surface 47 the valve 17 is induced downwardly and occupies its lower position as illustrated in Fig. 2; the vertical movement of the rollers is elected by the oscillation of the head 18 as a result of pulsations in the diapliragms.

The conduits 41 and 45 are arranged to be connected through suitable pipes," indicated by the dot and pick lines in the drawings, to

the teat cups shown in Fig. 3, each comprising a rubber sleeve 49 which terminates a a milk pipe 50, and which is surrounded by a cup-like member 51 preferably of rigid material, such as vulcanite or metal, the leads from the conduits 41 and 45 passing to the cu )s 51 and opening thereinto at 52.

n operation a suitable source of suction is connected to the'suction supply pipe 10, and the interior 2 of the casing 1 being opened to atmosphere, say through an aperture in the wall, the pulsator functions as follows.

In the position of the valve 17 shown in F ig. 1, the suction is conveyed through the conduitI 13 and the vannular cavity 40 to the conduits 41 and 42, the suction in the conduit 42 exhausting the space 44, and the space between the two diaphragms 3 and 6 being permanently exhausted by the constant suction applied through the conduit 12, the upper diaphragm 6 is in a state of equilibrium with the ircssures on each side balanced, while t-he diaphragm 3, is, under the action of the atmospheric pressure prevailing in the space 2, induced lo move upwardly carrying with it the upper diaphragm and the lever 24 and 25 with the consequence that the rollers 27 and 28 clear the peak 46 of the valve head and bearing on the cam surface 47 induce a down- 'ward Kmovement of the valve so that it is .caused to occupy the position shown in Fig. 2.

In this condition the sustion conduit 13 is cut olf from the-conduitv the bore 30 of the valve in the spaces 44 and 2 are balanced at atmospheric, but as the 6 is greater than that of the'dlaphragm 3 the actual pressure thereon is greater and results in a downward movement phragm 6 overcoming the resistanceof the diaphragm 3 so that the dl their original position as shown in Fig. 1, and the rollers ride over the peak 46 and bearino on the cam surface 48 return the valve 1 upwards again to the position shown in 7 Fig. 1.

These operations are repeated, and so long as suction-is applied to the pipe 10 with consequentially intermittent and alternate suction prevailing in the ing to the teat cups, an alternate collapse and expanse of the latter results and a flow of milk down the pipes 50which are themselves subjected to suction-is produced.

The speed of operation can be varying the bore of adjusted by the conduit 42 or a-lternatively by providing a suitable valve therein.

Referring now to the modified construction of pulsator illustrated in Fig. 4, where is arranged with an air space 55, at the head of which is located a diaphragm 56 mounted in a circular seating 57 of th position by an annular rlng 58 piece 61, between the head piece 61. v

63 is a suction supply pipe from which a conduit 64 opens into the space between the two diaphragms at 65 and maintains this space permanently exhausted, and a second conduit 66 in a slotted portion 67 ofthe casing leads to the distributing valve 53 sliding in a seating 68 operated by the pulsation of the diaphragms to distribute the suction to conduits associated with the teat Cups.

A head piece 69 secured to the 'lower diaphragm 56 by a bolt 70 maintains the diaphragms rigidly spaced, and attached to said l head piece 69 is a link 71,

the diaphragins, the motion vbeing transmitted 'from the diaphragms to the lever 72 throughthe link 71.

42 which through 17 communicates th with atmosphere, and as a result the pressures t area of the diaphragm of the diaiaphragms assume? conduits 41 and 45 passas an abutment for they springs 73 the other end of which bearsI on e bushin 76 so that the roller 74 ismainained on tie cam surface of the distrib-` uting valve. A y

The valve 53 has a port 79 which rin the upper position of the valve as shownin they gure, communicates the distributing conduit 66 with the conduit 80 with a further conduit 81 which opening at 82 into the closed space 62 between the upper `diaphragm '59 and the head 61 causesthe evacuation of this space. f

In the lower position of the valve the port 9 throws the distributing conduit 66'into communication with the conduit 83 andthe valve 53 is arranged as 1n the previous emto serve ,a dual purpose `of intermittently effecting exhaustion' of the closed space 62 to effect pulsation of the d iaphragms and consequent thereon to transmit inter- JA collar 78 serves `duits and 83 connected to the teat cups.

To this end the camsurface 75 of the valve is provided with declivities 84 and 85, on each of which the roller 74 bears, and it will be seen vwhen the roller clivity 85 thevvalve is forced upwardly to the position shown, causing the space 62 to be exhausted and the diaphragms to be moved upwardly as described in the previous embodiment, i

44 or 62. the conduit 45 or 83 in this mumcating with all four teat cups, and an intermlttent suction case combears on the lower de-l I one side, a suction conduit in sai at one side,

leading to the diaphragms and maintaining 1t evacuated, a

phragm insensitive to and unaffected by variations inthe degree of vacuum applied.

What I claim is:

1. A pulsator for milking machines comprisin a pair vof rigidly spaced diaphragme of di erent superficial area located 1n a casing, the smaller being open to atmos here at leading to the space enclosed between said diaphragms and maintaining it evacuated, a second suction conduit communicating -with a closed space between the larger diaphragm and the casing and havinga connection for the machine, and a valveconnected to said diaphragms andcontrolled by their position to openl said second space to atmosphere through said second conduit or to exhaust it therethrough, whereby such space is intermittently evacuated and second conduit and connection result.

2. A pulsator for milking machines comprising a pair origidly spaced diaphragms of different superficial area located 1n a casing, the smaller being open to atmosphere a suction conduit in said casing leading to the space enclosed between said diaphragms and maintaining it evacuated, a second suction conduit communicating with a closed space between the larger diaphragm and the casing and having a connection or the machine, a lever connected to said diaphragms, a valve and a cam surface on said valve engaged by said lever in such manner that during the movement o the diaphragms towards the valve the valve is moved towards them and vice versa, whereby said second space is intermittently evacuated and pulsations in the second conduit and connection result.

3. A pulsator for milking machines com- `prising a pair of rigidly spaced diaphragme of different superficial area located in a casing, the smaller being open-to atmosphere at one side, a suction conduit in said casing space enclosed between said second suction conduit communicating with a closed space between the larger diaphragm and the casing and having a connection for the machine, a lever connected to said diaphragms, a spring pressed roller on the end of said lever, a valve and a cam surface on said valve engaged by said roller in such manner that during the movement of the dias towards the valve the valve is moved towards them and vice versa, whereby said second space is intermittently evacuated and pulsations in the second conduit and connection result.

4. A pulsator for milking machines. comprising a pair of rigidly spaced diaphragme of different superficial area located in a casing, the smaller being open at one side to atmosphere, an annular head piece securing said diaphragms in position and forming casing pulsations in the with the larger diaphragm a closed space, a suction conduit in said casing leading to said -closed space and having a connection for the machine, a second suction conduit leadin to a second vclosed space between said iaphra s and maintaining it evacuated, and a va ve connected to said diaphragms and controlled by their position to open said first space to atmosphere through said first conduit or to exhaust it therethrough, whereby such s ace is intermittently evacuated and pulsations in said first conduit and connection result.

pulsatorffor .rililking nachinls com'- prising a pair o ri s ace ia ra s of dierent superflcigiil greg located in a ng, the smaller being open to atmosphere at one side, a suction conduit in said casin leading to the space enclosed between sai diaphragms and maintaining such space evacuated, a second suction conduit communicating with a closedspace between the larger diaphragm and the casing and having a connection for the machine, a valve and a cam surface on said valve, a lever connected to said diaphragms and spring urged into engagement with said cam surfacetransmitting movement of the diaphragms to the valve in such manner that said second conduit is intermittently submitted to suction and pulsation in the second conduit and connection produced.

6. A pulsator `for milking 'machines comprising a pair of rigidly spaced diaphragms of different superficial area located in a casing, the smaller being open to atmosphere at one side, a suction conduit in said casing leading to the s ace enclosed between tsaid diaphragme an maintaining such space evacuated. a second suction conduit communicating with a closed space between the larger diaphragm and the casing and having a connection for the machine, a bridge rigidly spacing said diaphragms and a head on said smaller diaphragm, a lever connected to said head, a spring pressed roller on the end of said lever, a slide valve operating said second conduit and a cam surface on, said valve engaged by said roller in such manner that during the movement of the diaphragms towards the valve the valve is moved towards them whereby said second conduit is intermittently evacuated and pulsations in the' second conduit and connection result.

7. A pulsator for milking machines, coinprising a pair of rigidly spaced diapliragms of different superficial area, suction means maintaining the space between the diapliragms evacuated, a connection from said suction means to the machine, conduits for alternately applying the suction and atmosplieric air to the outer` face of the larger diameans and the machine and means opera-y tively connecting the valve to the diaphragms' whereby each change in pressure on the larger diaphragm is automatically produced by the ,last pressure change actuating the valve,

.whereby the valve automatically interrupts and renews the suction to the machine causing pulsations therein.

8. A pulsator for milking machines comprising a pair of rigidly spaced diaphragms of different superficial area suction'means for maintaining the space between them evacuated and for applying the suction to the outer A face of the larger diaphragm, a connection between the suction means and the machine, and a Valve disposed to interrupt theappli'cation .of suction tothe larger diaphragmand to the machine and,v formed to admit atmospheric V`air thereto, said valve being operativelycorp-- nected vto the diaphragriis wherebyeach change of pressure on the larger diaphragm -v automatically interrupts thel suction to the;

machine so as to cause pulsations therein.

9; A. pulsator for milking machines .comprisingja pair. of-rigidly spaced` diaphragms of different superficial area-y suction means for:

maintaining'the space between them evacuated, and for applying 'the suction to theouter face ofthe largervdiaphragm, apairfof con- 'l nections betweenthe suction means andl the v machine, and a valve disposed to-interrupt the said application off suction to the larger i diaphragm, .and tothe :connections to the machine and formed'to admit atmospheric air' thereto, said valve being operatively con# nected to the diaphragms whereby each change of pressure on the larger diaphragm automatically interrupts the suction to one of the connections to the machine and admits air through the other so as to cause pulsations in both said connections alternately.

In testimony-whereof I aflix my signature.

ALEXANDER FREDERICK PLINT. 

